In the original discussion, one mom said her family disallowed any humor about WWII, saying nothing about the war was funny, so she coudln't watch this program.

I wrote:

I think adults enjoyed the humor about incompetent and comical Germans. The kids enjoyed the escape tunnel and the funny planning.

I didn't ask my dad anything about it, He had been on his way to Europe on a troop ship when the war ended. He was there two years, first in France and most of the time in Germany, taking care of army vehicles, mostly. It wasn't a show we watched with parents, though.

In youtube comments, someone has transcribed the words to the themesong (which wasn't sung on TV, but on a recording elsewhere). It explains some more of the intention of the humor. Reluctant or accidental heroes, or a tongue-in-cheek commentary on the over-use of "hero."

I made a couple of corrections, but it still not be exactly right.

Heroes, heroes, husky men of war,
Sons of all the heroes of the war before.
We're all heroes up to our ear-o's
You ask the questions
We make suggestions
That's what we're heroes for.

All good heroes love a good, big fight
Open up the bomb bays, brighten up the night.
We earn laurels solving your quarrels
You throw the roses,
We punch the noses,
That's what we're heroes for.

What's a hero do?
Well, we're not gonna tell ya
Cause we wish we knew.
That's why we heroes are so few.
We've got a slogan
From Colonel Hogan
And Colonel Hogan's a hero too.

Never flinch, boys, never be afraid,
Heroes are not born, boys, heroes all are made.
Ask not why, boys, never say die, boys,
Answer the call, remember we'll all be heroes forever more.

Wikipedia says, of the song: "The theme music was composed by Jerry Fielding, who added lyrics to the theme for Hogan's Heroes Sing The Best of World War II – an album featuring Dixon, Clary, Dawson, and Hovis singing World War II songs."